ICA Calculation (International Competitive Advantage Index)

04 Jul 2018, 15:10

Hi all,

does anyone know how to compute the International Competitive Advantage Index (ICA) in Stata? For example, if we would have the following dataset (Note: It is not in -dataex-, but that is because I do not have this data in Stata yet):

A

B

ICA

1

10

1.25

1

10

1.25

1

20

0.83

1

30

0.83

2

20

1.67

2

30

1.67

3

10

1.25

3

20

0.83

3

30

0.83

3

10

1.25

If the first two variables are given, I would like to compute variable ICA in Stata. The ICA Index is computes as follows:

ICA_ab = (C_ab / C_b) / (C_a / C_n)

where
C_ab = is the number of observations of variable A for a given observation b of variable B.
C_b = is the total number of observations b of variable B.
C_a = is the total number of observations a of variable A.
C_n = is the total number of observations (number of rows).

To make this clear, these variables would take on the following values for the first ICA index:
C_ab = 2 (because the 10 exists twice for all the 1s in variable A)
C_b = 4 (there are four 10s in variable B)
C_a = 4 (there are four 1s in variable A)
C_n = 10 (there are 10 rows)
Hence, the ICA for the first row computes to 1.25.